811220651 has 2 divisors, whose sum is σ = 811220652. Its totient is φ = 811220650.

The previous prime is 811220623. The next prime is 811220681. The reversal of 811220651 is 156022118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 811220651 - 2¹⁸ = 810958507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 811220651.

It is not a weakly prime, because it can be changed into another prime (811220621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405610325 + 405610326.

It is an arithmetic number, because the mean of its divisors is an integer number (405610326).

Almost surely, 2^811220651 is an apocalyptic number.

811220651 is a deficient number, since it is larger than the sum of its proper divisors (1).

811220651 is an equidigital number, since it uses as much as digits as its factorization.

811220651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 811220651 is about 28481.9355206067. The cubic root of 811220651 is about 932.6377694177.

Adding to 811220651 its reverse (156022118), we get a palindrome (967242769).

The spelling of 811220651 in words is "eight hundred eleven million, two hundred twenty thousand, six hundred fifty-one".